1. Field of the Invention
The present invention relates to a user interface and an input method for a mobile terminal, and more particularly, to a virtual wheel interface structure of a mobile terminal having a wheel input unit and to a character input method using a virtual wheel interface.
2. Description of the Prior Art
With recent developments in the technologies of integrated circuits for semiconductors and of information and communication, various mobile terminals such as a mobile phone, PDA (personal digital assistants), MP3 player, digital camera, and PMP (portable multimedia player), have become widely available. Most of all, mobile terminals are small in size allowing users to conveniently carry them. In the case of a mobile terminal adopting an input device such as a conventional keyboard system, there are inevitably various limitations in human engineering and design.
For this reason, some mobile terminals such as an MP3 player and a PMP omit a character input function, and optimize operational functions (for example, menu selection or musical selection) by using a navigation key and a wheel key as input units. However, according to a recent trend in the integration of specific functions of terminals, adoption of a character input function is required even for mobile terminals currently having no character input function. Further, as competition becomes more intense, mobile terminal manufacturers are endeavoring to improve the competitiveness of their products by adopting character input function.